It would save about $20 Billion per year.
In aggregate military spending (VA+DoD+DoE+"Foreign aid"), we we spend about ~$720 Billion per year. (No one knows what the CIA budget is)
This does not include the War in Afghanistan (which we are losing), which costs over $120 Billion per year.
This also does not include other military operations
The Department of Homeland Security and Department of Justice's agencies combined cost over $88 Billion.